A person is exposed to various audio, video, and signal sources over time. For example, the person may listen to a radio station in the morning, attend a conference during the work day, watch a television show in the evening, and participate in a social gathering at night. Throughout these different activities, the person can actively listen to audio signals by, for example, tuning to a talk show broadcasted over the radio station. The person can also passively hear audio signals by, for example, being unaware of the background music played at the conference. Regardless of whether the exposure is active or passive, the person may be interested in a persistent or continuous monitoring of the signals. This monitoring allows the person to increase his or her environmental awareness of the signals he or she is actually exposed to in comparison to the signals he or she likes to be exposed to. For example, if the person dislikes a certain music genre and becomes aware that a frequently visited coffee shop plays that genre, the person is empowered to frequent a different coffee house. Additionally, the person may also be interested in receiving specific services based on the exposure. For example, if the person is a fan of a certain television show, he or she may be interested in receiving merchandise related thereto.
Current techniques do not allow this type of continuous monitoring and services derived therefrom. For example, when the person is actively listening to a song, the person can record the song on a piece of paper or via an electronic device. If the person is not familiar with the song, the person can activate a song recognition application running on an electronic device. However, such techniques require the person's active input to monitor each song he or she is actively listening to. Thus, these techniques are prone to errors and become prohibitive when monitoring songs over time. Additionally, these techniques do not allow the monitoring of signals that the person is passively exposed to.
Other current techniques that do not involve active input from the person have been used but present many disadvantages. For example, audience measurement systems for measuring television or radio audiences make use of so-called meters installed in a panel of households that are generally chosen such that their occupants are demographically representative of the potential audience population as a whole. The meters are devices that monitor and record information related to channels, stations, or programs selected for viewing or listening on a television or radio in the household. The meters report the information to a central office that has access to reference information related to all channels, stations, or programs available for viewing. The central office can compare the received household information to the reference information to determine the exposure of the audience, as a whole, to the channels, stations, or programs. However, the use of meters is costly and invasive as it requires dedicated circuitry installed in the households. Additionally, the monitoring is limited to exposures at the households and, thus, produces incomplete data.
Even, when a meter is designed as a personal electronic device that can be attached to a user, the meter needs to be reliable. Otherwise, inaccurate data is generated. When the number of deployed personal electronic device-like meters increase, the size of the data generated by the meters and the size of the data received, searched, and compared at the central office increase drastically. This increase in data size limits the number of deployable meters and truncates the data collected at each meter, which results in an incomplete data set and in an inability to provide personal services based on individual exposures.